Cooling device for cylindrical electrical components



Nov. 25, 1969 E. JAGER 3,480,078

COOLING DEVICE FOR CYLINDRICAL ELECTRICAL COMPONENTS "Filed Nov. 21. 1967 In van/0r:

EDWIN JAG-ER BY 3%, W "92222;

ATTORNEYS Unitcd States Patent U.S. Cl. 165-185 6 Claims ABSTRACT OF THE DISCLOSURE At least a pair of longitudinally extending semi-cylindrical envelope segments, each provided with a plurality of axially extending cooling ribs, with the segments adapted to be fitted together about a cylindrical electrical component to form a substantially complete cylindrical envelope about the component, the inner bore of which is in intimate abutting contact with the cylindrical surface of the electrical component to form a heat dissipating and cooling device, and the outer edges of the cooling ribs provided with recesses into which a spring ring is engageable for holding the segments in intimate contact with the electrical component.

The present invention relates to cooling devices for cylindrical electrical components, e.g. transistors and other semiconductor devices or electrical discharge tubes. These electrical components are usually arranged in a cylindrical casing which it is necessary or desirable to cool.

It is an object of the present invention to provide a cooling device for this purpose which is simple to produce and use.

The present invention provides a cooling device for a cylindrical electrical component, comprising at least two cylindrical envelope segments which together form an at least almost complete cylindrical envelope for abutment against the electrical component with good surface contact, and which are provided with axially parallel cooling ribs having at the outer edges of the ribs recesses which are situated in a diametral plane of the cylindrical envelope, an open spring ring being engageable in the recesses for pressing the segments in the radial sense.

Each cylindrical envelope segment may be extruded in one piece with its cooling ribs. The cylindrical envelope segments and the cooling ribs preferably comprise aluminum. At least the outer sides of the cylindrical envelope segments and the cooling ribs are preferably blackened.

The spring ring may be an open wire ring.

The cylindrical envelope segments may be intended to abut over their entire inner surfaces against the cylindrical electrical component, in which case the recesses at the edges of the cooling ribs of the cylindrical envelope segments may be arranged midway along the axial length of the cooling device. To improve the cooling effect, the axial length of the cooling device may be greater than the axial length of the cylindrical electrical component, the cylindrical envelope segments being intended to abut along part of their length against the cylindrical electrical component, in which case the recesses are at least approximately midway along the length of said part.

The invention will be more readily understood from the following description, given by way of example, of the embodiments thereof illustrated in the accompanying drawing, in which:

FIGURE 1 is a plan view of a transistor with a cooling device,

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FIGURE 2 is a sectional view taken on the line II-Il of FIGURE 1,

FIGURE 3 is a view corresponding to FIGURE 2 showing a modification of the cooling device of FIGURES 1 and 2.

In FIGURES 1 and 2 reference numeral 1 designates the cylindrical casing of a transistor the cooling of which is effected by the cooling device which will be described hereinafter. This cooling device comprises two cylindrical envelope segments 2 with cooling ribs 3 and an open spring ring 4. The segments 2 together form an almost complete cylindrical envelope; they abut on the cylindrical casing -1 of the transistor, for which purpose their inner side has the same radius of curvature as the outer side of the casing 1. Since the segments form only an almost complete cylindrical envelope, they are separated from one another by narrow gaps 5. The cooling ribs 3 extend parallel to the geometric axis 6 of the segments 2. Each of the segments 2 is made together with its cooling ribs 3 from a single aluminum extrusion and is blackened in order to improve heat radiation. The cooling ribs 3 each have a recess 7 at the outer edge. These recesses 7 are situated in a diametral plane of the cylindrical envelope midway along the axial length of the segments 2, which corresponds to the axial length of the casing 1. The spring ring 4 is an open wire ring which is arranged in the recesses 7 and presses the segments 2 with the cooling ribs 3 in the radial sense, whereby these are pressed against the casing 1 of the transistor in order to establish thermal contact therewith.

The modification shown in FIGURE 3 differs from the embodiment shown in FIGURES 1 and 2 in that the axial length of the segments 12 and cooling ribs 13 is greater than the axial length of the casing 1 of the transistor, and the diametral plane in which the recesses 17, in which the spring ring 4 is situated, are arranged is not situated midway along the axial length of the segments 12 but that of the axial length of the casing 1. The spring ring 4 acting offset from the midpoint of the length of the segments 12, but midway along the length of the casing 1, exerts a constant pressure in the region of the contact surface between the segments and the casing 1. This modification shown in FIGURE 3 has a greater cooling capacity than the embodiment shown in FIGURES 1 and 2.

The cooling device described is simple and correspondingly cheap to produce, since it consists only of parts which can easily be extruded, and a spring ring. This cooling device is simple to use; it can easily be applied to a cylindrical electrical circuit component and removed therefrom again e.g. if such an element is replaced by another. Since the cooling device described comprises two parts held together resiliently, reliable thermal contact is guaranteed even if the diameter of the cylindrical electrical circuit component deviates within certain tolerance limits from the nominal diameter which the segments of the cooling device are intended to match.

What I claim is:

1. A cooling device for a cylindrical electrical component which is readily connectable thereto and removable therefrom, comprising at least a pair of unitized similar cylindrical envelope body segments having inner and outer wall portions with the same radius of curvature as the electrical component, the inner wall portions of said body segments together forming a cylindrical envelope adapted for intimate abutment against the electrical component with good surface contact between the electrical component and said inner wall portions, more than a pair of cooling ribs integrally extruded in one piece with each body segment, said cooling ribs of each body segment being coextensive therewith and extending radially outwardly from and spaced circumferentially about the respective outer wall portion in axially parallel relation, each cooling rib having an outer free edge, and opposite ends, a recess in the outer free edge of each cooling rib of each body segment intermediate the opposite ends thereof thereby providing a plurality of recesses about said cooling device in a diametrical plane of the envelope which plane is in a medial portion of the cylindrical envelope, and an open spring ring resiliently engaged in said recesses for pressing the body segments radially inwardly to provide intimate contact between said inner wall portions and the electrical component, whereby the unitized body segments of the cooling device are resiliently movable relative to each other for ease in connecting said device to and removing it from an electrical component.

2. A cooling device according to claim 1, wherein the cylindrical envelope body segments and the integral cooling ribs are comprised of aluminum.

3; A cooling device according to claim 1, wherein at least the outer wall portions of said envelope body segments and the cooling ribs are blackened.

4. A cooling device according to claim 1, wherein the spring ring is an open wire ring.

5. A cooling device according to claim 1, wherein the recesses at the edges of the cooling ribs of the cylindrical envelope body segments, which are intended to abut over their entire wall portions against the cylindrical electrical component, are arranged midway along the axial length of the cooling device.

6. A cooling device according to claim 1, wherein the recesses at the edges of the cooling ribs of the cylindrical envelope body segments, which are intended to abut along part of their axial length against the cylindrical electrical component, are arranged at least approximately midway along the length of said axial length part.

References Cited UNITED STATES PATENTS 5/1920 Guyer 165-183 2/ 1962 Allison 16580 

